Believing it not to be loaded, Kendrick fired the rifle at the 23-year-old Fijian as he slept on his bunk, hitting him in the head.

Colleagues fought to save Rifleman Vakabua but he was pronounced dead minutes later.

The shooting happened in June last year inside dictator Saddam Hussein's former palace in Basra, which the soldiers' unit had taken over as their headquarters.

Aaron Kendrick (left) is alleged to have shot Edward Vakabua in the head with a sniper rifle as he slept

Prosecutor Colonel Nigel Jones told the hearing at Bulford, Wiltshire, that Kendrick, of 4th Battalion The Rifles, took the L96 bolt-action rifle from beneath a colleague's bed.

He was neither allowed nor qualified to use it, but dreamed of becoming a sniper himself.

Rifleman Vakabua was hailed a hero shortly before his death.

Mr Vakabua had saved a wounded colleague.

Prosecutor Colonel Nigel Jones said: 'It was not his rifle.

'He was not authorised to use it and he was not qualified to use it.

'He picked up the rifle because he was curious, because he was interested in going on a course and qualifying as a sniper.

'His father was also qualified on this rifle and he wanted to follow in his father's footsteps.

'He was in his own words 'messing about' to see how quickly he could load the rifle.

'He committed the cardinal sin of weapon handling - he pointed it in jest at another soldier.

'He cocked the rifle and, in a standing position, he pointed it in the direction of Rifleman Vakabua, who was laying on his bed a few metres away having nap.

Edward Vakabua was shot in the head while based at Saddam Hussein's presidential palace in Basra

Edward Vakabua was shot in the head while based at Saddam Hussein's presidential palace in Basra

'To cap it all, he put his finger on the trigger and pulled the trigger, discharging one round which shot Rifleman Vakabua in the head and killed him.

'Rifleman Kendrick's actions, in his handling or mishandling of the rifle, showed wanton disregard for normal safety precautions, which he, as a trained infantry soldier, was aware of.

'It was that gross negligence which directly resulted in the tragic death of Rifleman Vakabua.

'It is on this basis that the Crown says the accused is guilty of manslaughter.'

Kendrick was deployed to Iraq in March 2007 and was based in a 'cluttered and cramped room' at Basra Palace with several colleagues, including Rifleman Vakabua.

The court martial heard that only two men in his platoon, Lance Corporals Leigh Pool and Frank Taylor, were trained to use the sniper rifle and they both shared the same weapon.

The panel was shown the rifle used in the fatal shooting, which is fitted with a telescopic sight and a bi-pod, and covered in desert camouflage cloth.

Col Jones said that on June 6 last year, L Cpl Taylor collected the rifle from L Cpl Pool, and took it back to his room, which he also shared with Kendrick.

L Cpl Taylor stashed the gun under his bunk while he went to collect further equipment for a strike operation, leaving a loaded magazine in it.

It was while L Cpl Taylor was out of the room for a few moments that Kendrick decided to fiddle with the rifle and shot his sleeping comrade.

Kendrick was interviewed by police and admitted accidentally firing the rifle at Rifleman Vakabua, known as Vaka to his friends.

But he claimed he was not entirely to blame because he said the gun should not have been left with a loaded magazine in it.

Orders at the time were that no weapons should be left loaded inside the barracks.

But the court martial heard the platoon's two snipers regularly left 10-round magazines in the gun so they were prepared for emergencies.

Kendrick told police: 'I had that gut instinct it was safe.'

Kendrick has pleaded guilty to a charge of conduct prejudice of good order and military discipline through inappropriate and negligent handling of a weapon.

The soldier, who had been in the army 18 months at the time of the shooting, denies manslaughter.

Giving evidence, L Cpl Taylor said he walked back into his room to see Kendrick brandishing the sniper rifle.

He said: 'The L96 was on his right shoulder and he was standing up, pointing it at where Vaka was sleeping.

'It was just a split second between me seeing him and hearing the shot.

'I looked to see where the shot had hit and rushed over to Vaka's bed space. I then saw that he had sustained a head injury.'

Fijian L Cpl Taylor described Rifleman Vakabua as 'a quiet, happy person who was well-liked by everyone in the platoon'.

Rifleman Vakabua, from Suva, Fiji, was hailed a hero shortly before his death for his role in saving a wounded colleague during an attack.

He was manning a vulnerable rooftop observation post in Basra when it suffered a direct hit from an insurgent mortar, severely injuring a fellow soldier.

He braved intense mortar fire after he volunteered to drive the man to a helicopter landing site for evacuation to hospital.

Kendrick has pleaded guilty to a charge of conduct prejudice of good order and military discipline through inappropriate and negligent handling of a weapon, but he denies manslaughter. The hearing continues.